Plant and method for coagulting pasteurizing and cooking food

ABSTRACT

A plant and method for coagulating, pasteurizing and cooking food having a liquid or pasty base including a plurality of stations, devices for implementing a processing step on the food in each station, at least one container into which the food to be processed is initially placed, and devices for enabling the container(s) to be successively positioned in the stations to thereby subject the food in the container(s) to processing by the processing devices in the stations. The processing device in at least one station includes a variable-speed dynamic radial heat exchanger for affecting the temperature of the food.

FIELD OF THE INVENTION

This invention relates to a coagulation and/or pasteurization and/orcooking plant for food substances, and in particular a cheese and/orricotta-making plant.

BACKGROUND OF THE INVENTION

Various types of batch or continuous coagulation plants are known, eachbeing designed specifically for a particular type of cheese. A typicalexample of this specialization is a plant for producing grana cheese DOC(controlled origin name) such as reggiano parmesan, grana padano and thelike which, being obtained from crude milk, does not require a milkpasteurization section upstream, as in the case of a plant formozzarella, stracchino or taleggio production. Other examples are thevarious plants for producing cooked or raw cheeses. In the case ofreggiano parmesan, montasio, pecorino sardo, provolone and similarcheeses, the curd, after coagulation and cutting, has to be cooked atvarious temperatures and for various times depending on the type ofcheese. Other examples are specific plants for mozzarella, taleggio,stracchino and the like, in which there is no cooking section.

Even today, specific plants for each individual type of cheese are builtand used. Hence a cheese dairy is able to produce only those types ofcheese allowed by the installed plants, so that if a cheese dairycontains only plants for reggiano parmesan production it is unable toproduce mozzarella, stracchino or taleggio, and likewise a taleggiocheese dairy can never produce reggiano parmesan or gran padano cheesebecause its plants and equipment do not allow it. Consequently acharacteristic of cheese dairy plants of the known art is theirproduction rigidity. Even continuous coagulation plants, of more recentappearance on the market, have the same limitation, which in fact iseven more restrictive as they possess no flexibility at all. In thisrespect, in addition to being able to produce only the specific type ofcheese for which they have been designed, they have a rigid hourlyproductivity. Such plants are also limited to coagulation plus cuttingand partial drainage of the curd.

An example of the known continuous plants for producing soft cheese isthe apparatus for coagulating liquid-milk products as disclosed in U.S.Pat. No. 3,918,356. The apparatus comprises: a circular trackway havingsmoothy surfaced rails; a plurality of wheel frames positioned on wheelsthat overlie and travel on said circular trackway, said wheel framesbeing rigidly linked to each other; a corresponding number of identicalcontainer or vats that are pivotally mounted to said wheel frames and atipping means intermediate said wheel frames and said vats to allow eachvat to be independently tipped relative to the respective wheel frame; afilling station comprising overhead means relative to said vats for theaddition of liquid milk product and coagulations agents to said vats; acutting station comprising overhead cutting means relative to said vatsthat is moveable and insertable into each vat for cutting curd as itcoagulates; a discharge station comprising a discharge chute positionedcircumferentially about said circular trackway for receiving the wheyand coagulated curd formed from at least two adjacent vats, said chuteextending in a downwardly direction from an upper end where the whey andcurd are received from said vats, to a lower end to which the whey andcurd is transported; and a drive means for sequentially displacing saidwheel frames over said circular trackway in predetermined spaced timerelationship at constant velocity from said filling station to saidcutting station to said discharge station.

An example of the known continuous plants for producing soft cheese isthe apparatus for coagulating liquid-milk products as disclosed in U.S.Pat. No. 3,918,356. The apparatus comprises: a circular trackway havingsmoothy surfaced rails; a plurality of wheel frames positioned on wheelsthat overlie and travel on said circular trackway, said wheel framesbeing rigidly linked to each other; a corresponding number of identicalcontainer or vats that are pivotally mounted to said wheel frames and atipping means intermediate said wheel frames and said vats to allow eachvat to be independently tipped relative to the respective wheel frame; afilling station comprising overhead means relative to said vats for theaddition of liquid milk product and coagulations agents to said vats; acutting station comprising overhead cutting means relative to said vatsthat is moveable and insertable into each vat for cutting curd as itcoagulates; a discharge station comprising a discharge chute positionedcircumferentially about said circular trackway for receiving the wheyand coagulated curd formed from at least two adjacent vats, said chuteextending in a downwardly direction from an upper end where the whey andcurd are received from said vats, to a lower end to which the whey andcurd is transported; and a drive means for sequentially displacing saidwheel frames over said circular trackway in predetermined spaced timerelationship at constant velocity from said filling station to saidcutting station to said discharge station.

OBJECTS AND SUMMARY OF THE INVENTION

These objects are attained by the plant of the present invention,comprising: a plurality of stations (A, B, C, D, E and F), each stationprovided with devices (15; 16; 16, 17; 18, 19; 19,16; 18 respectively)for implementing a determined processing stage, a variable-speed dynamicradial heat exchanger being provided in the stations in which a heatexchange is required; and means for enabling a container (22), intowhich the food substance to be processed is initially fed, to besuccessively positioned in correspondence with the various stations (A,B, C, D, E and F) for executing the required process.

A further object of the present invention is to provide cheese dairieswith a plant and production process providing considerable versatilityof utilization to the extent of enabling any type of cheese to beproduced, and comprising not only a coagulation and breakdown sectionbut also pasteurization, cooking and reheating sections.

A further object of the invention is to drastically reduce plantinvestment costs, and to be able to produce that type of cheese which atthat particular moment is economically the most advantageous for themarket.

A further object of the invention is to provide a plant which is easyand economical to use without the need to employ specialized labor orcomplex techniques, so enabling the technician to maintain producttypicality without having to undergo special plant training.

Said objects are attained by the plant of the present invention,comprising:

plurality of stations (A, B, C, D, E and F), each station being providedwith devices (15; 16; 16, 17; 18, 19; 19,16; 18 rispectively) forimplementing a determined processing stage, a variable-speed dynamicradial heat exchanger being provided in the stations in which a heatexchange is required; and

means for enabling a container (22), into which the food substance to beprocessed is initially fed, to be successively positioned incorrespondence with the various stations (A, B, C, D, E and F) forexecuting the required process.

It should be noted that the stations can be fixed and the containerscontaining the substance to be processed, such as milk or whey, bemovable, or the containers can be fixed and the stations be movable, orboth the containers and stations can be movable.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more apparent from the description of oneembodiment thereof given hereinafter. In this description reference ismade to the accompanying drawings, in which:

FIG. 1 is a schematic representation of the plant according to thepresent invention, shown extended in length and provided with sixstations (A, B, C, D, E and F) and eight positions (indicated by Arabicnumerals), which is particularly suitable for milk coagulation;

FIG. 2 is an enlarged schematic view of a particular intermediatestation of the plant (station B), observed from a different viewpointthan FIG. 1; and

FIG. 3 is a schematic view of a container of the plant of FIG. 1 in thesituation in which it appears on reaching the last station (F) of theplant.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to said figures, the plant according to the presentinvention comprises: a monorail 10 on which the various operatingstations A, B, C, D, E and F are movably installed, all provided withlifting means 13. The lifting means 13 carry a relative fixing means 14,to which various devices for implementing a determined processing stage,for example proportioning devices, heat exchangers, agitators and otherdairy equipment, can be fixed.

Specifically, in station A, coinciding with position 1 (FIG. 1) aproportioning device 15 of known type, provided with a level regulatorfor filling the first container 22, is fixed to the fixing means 14,which consists basically of a horizontal plate connected to the relativelifting means 13. To the plate 14 of station B (coinciding with position2) there is flanged a variable-speed dynamic radial heat exchanger 16(in this respect see Italian patent application MO093A000005 andPCT/EP95/03062 both in the name of the present applicant). In station C(coinciding with position 3), to the plate 14 of a first lifting means13 there is flanged a further variable-speed dynamic radial heatexchanger 16, on the plate 14 of a second lifting means 13 there beinginstalled a double proportioning device 17. The stations D and E(positions 6 and 7 respectively) are both provided with double liftingmeans 13 with relative plates 14. On the first plate 14 of station Dthere is installed a variable-speed agitator 18 and on the other plate14 a variable-speed curd knife 19. On the first plate 14 of station Ethere is also installed a variable-speed curd knife 19 and to the otherplate 14 there is flanged a further variable-speed dynamic radial heatexchanger 16. A variable-speed agitator 18 is installed on the plate 14of station F (position 8). At station F (FIGS. 1 and 3) there isprovided a device 20 for lifting the container 22, the lifting device 20being shown in its maximum extended position in FIG. 1, the container 22when in this situation being shown dashed in FIG. 3.

From FIGS. 1 and 2, it can be seen that a pneumatically or mechanicallyoperated bar or chain 21 of pawl type intermittently moves thecontainers 22 through one station (as indicated by the series of arrowsbelow the containers), but only when the lifting devices 13 are in theirupper end-of-travel position.

The plant according to the present invention operates briefly as followswhen used for cheese-making from milk. At commencement of processingwith the plant at rest, all the stations have their processing devicesraised and at rest. On commencing processing, in position 1 the liftingmeans 13 of station A causes the proportioning device 15 to descend inorder to fill the container 22 in position 1 as far as the predeterminedlevel. On attaining this level the proportioning device 15 ceases tofeed milk to the container 22, is closed and is raised by the liftingmeans 13 into the rest position. The pawl bar or chain 21, driven byappropriate drive means (not shown), is now operated to shift allcontainers 22 through one position. Consequently that container 22 whichwas in position 1 passes to position 2 (in correspondence with stationB) and so on, until the last container 22, which was in position 8(station F), passes to position 1 (station A). The container 22 now inposition 1 is filled while at the same time in position 2 the dynamicradial heat exchanger 16 of station B is immersed into the relativecontainer 22 by operating the corresponding lifting means 13. Thedynamic radial heat exchanger 16 raises the temperature of the milkcontained in said container 22 to the preset pasteurization temperature,after which the lifting means 13 raises the heat exchanger 16 into itsrest position. At this point the chain 21 again moves the turntablecontaining the containers 22 through one position, so that the heatedmilk in the container 22 previously in position 2 is now in position 3(station C). At this point the already described operations are repeatedin positions 1 and 2, whereas in position 3 the dynamic radial heatexchanger 16 of station C is lowered by the relative lifting means 13 tocool the milk to the required coagulation temperature.

As shown in FIG. 1, the lifting means 13 and the drive means of the pawlbar or chain 21 are controlled by electronic control means which, as isconventional in the art, include a microprocessor device.

During this temperature decrease, the double proportioning device 17,which is lowered by the relative lifting means 13, feeds the requiredmilk ferments into the corresponding container 22 at the requiredtemperature, and then feeds the curding liquid into the milk. When thetwo lifting means 13 of stations A, B and C have raised the relativeprocessing devices, the pawl chain 21 shifts the containers 22 through afurther position. Specifically the container 22 which was in position 3passes into position 4, which is a rest position allowing the coagulumor caseins to set. When the operations in positions 1, 2 and 3 haveterminated, the pawl chain 21 again shifts the containers 22 through afurther position, so that the container 22 in position 4 passes toposition 5, which is a further casein setting position. When the usualprocesses in positions 1, 2 and 3 under the control of the relativestations have terminated, the pawl chain 21 again shifts the containers22 through one position, to bring the container 22 previously inposition 5 into position 6 (station D), where the lifting means 13immerse into the container 22, in succession, the curd knife 19 forcutting the curd and the agitator 18 for maintaining the contents underagitation even when the curd knife 19 has ceased to act and has beenwithdrawn. The agitator 18 is withdrawn after a predetermined time,enabling the pawl chain 21 to shift the container 22 previously inposition 6 into position 7 (station E). The already described operationsare repeated by the relative stations in positions 1, 2, 3 and 6,whereas in position 7, simultaneously with final curd cutting by thecurd knife 19, the dynamic radial heat exchanger 16 of station E cooksthe curd granules of the required dimensions at the requiredtemperature.

When the various processing devices have been withdrawn from therelative containers 22, the pawl chain 21 again shifts the containers 22through one position, to move that previously in position 7 intoposition 8 (station F). In this latter position the relative liftingmeans 13 lowers the agitator 18 to maintain the curd agitated in thewhey while the containers 22 are emptied, either by raising (FIG. 3) orby suction by means of a pump. When the container 22 has been completelyemptied and the agitator 18, preferably provided with known spry balls,has been withdrawn, the pawl chain 21 shifts the empty washed containers22 so that the container in position 8 is moved into position 1, thecycle then being repeated as described or with technical variations toproduce another type of cheese or ricotta. It should be noted that thesame result can be achieved by maintaining the containers 22 at rest andshifting the stations with their relative processing devices.

As will be apparent, in the aforedescribed plant the cheese-makingprocesses take place in the six containers located in positions 2, 3, 4,5, 6 and 7, with the exclusion of positions 1 and 8 which serverespectively for filling the containers and for emptying and washingthem. On the basis that the average residence time in each position isabout 10 minutes, any cheese-making process can be completed in aboutone hour.

It should be noted that the aforedescribed cheese-making procedure isthe most complex, comprising every possible cheese-making process. Theflexibility of the plant however enables a different cheese-makingprocedure to be programmed by varying the succession of operations fromposition 2 to position 7.

The plant production rate depends on the capacity of the containers 22.

In this respect, if the containers 22 have a capacity of 600 liters, thehourly production is 3600 liters. If instead the containers 22 are ofdouble capacity, ie 1200 liters, the hourly production is 7200 liters. Aproduction run of eight hours would therefore treat 28800 liters of milkin the first case and 57600 liters of milk in the second case.

It should be noted that the plant of the present invention can alsoprocess milk mixed with other substances, for example corn or maizemeal, and in the limit can be used for making polenta, goulash orminestrone, for example by feeding water and maize meal or therespective ingredients into the container 22 in position 1, cooking itin position 7 and discharging it in position 8, without using the otherpositions.

In the limit each container could be used for different preparationsthan those of the other containers (for example, milk could be fed intoone container for cheese-making, water and maize meal into anothercontainer, water and chopped vegetables into a third container forminestrone, and so on).

It should also be noted that the plant of the invention is convenientlycontrolled and programmed by conventional electronic control means, forexample one or more microprocessor devices.

I claim:
 1. A plant for coagulating, pasteurizing and cooking foodhaving a liquid or pasty base, comprising:a plurality of stations,processing means for implementing a processing step on the food in eachof said stations, said processing means in at least one of said stationscomprising a variable-speed dynamic radial heat exchanger for affectingthe temperature of the food, at least one container into which the foodto be processed is initially placed, and positioning means for enablingsaid at least one container to be successively positioned in saidstations to thereby subject the food in said at least one container toprocessing by said processing means in said stations.
 2. The plant ofclaim 1, wherein said stations are fixed and said at least one containeris movable.
 3. The plant of claim 1, wherein said stations are movableand said at least one container is fixed.
 4. The plant of claim 1,wherein said station comprises six stations,said processing means in afirst one of said stations comprising a proportioning device and liftingmeans for moving said proportioning device relative to said at least onecontainer when in said first station, said proportioning device beingarranged to fill said at least one container when in said first stationwith milk or whey; said processing means in a second one of saidstations comprising a variable-speed dynamic radial heat exchanger andlifting means for moving said heat exchanger relative to said at leastone container when in said second station, said second station thusconstituting said at least one station, said processing means in a thirdone of said stations comprising a variable-speed dynamic radial heatexchanger, first lifting means for moving said heat exchanger relativeto said at least one container when in said third station, a doubleproportioning device and second lifting means for moving said doubleproportioning device relative to said at least one container when insaid third station, said double proportioning device being arranged tofeed said at least one container with milk ferments and curding liquidwhen in said third station, said processing means in a fourth one ofsaid stations comprising a variable-speed agitator, first lifting meansfor moving said agitator relative to said at least one container when insaid fourth station, a variable-speed curd knife and second liftingmeans for moving said curd knife relative to said at least one containerwhen in said fourth station, said processing means in a fifth one ofsaid stations comprising a variable-speed curd knife, first liftingmeans for moving said curd knife relative to said at least one containerwhen in said fifth station, a variable-speed dynamic radial heatexchanger and second lifting means for moving said heat exchangerrelative to said at least one container when in said fifth station, andsaid processing means in a sixth one of said stations comprising avariable-speed agitator and first lifting means for moving said agitatorrelative to said at least one container when in said sixth station,further comprising means for emptying said at least one container of itscontents when in said sixth station and means for cleaning said at leastone container after it has been emptied.
 5. The plant of claim 4,wherein said at least one container comprises eight containers, furthercomprising a train of said eight containers shiftable intermittentlybetween eight positions, a first one of said positions coinciding withsaid first station, a second one of said positions coinciding with saidsecond station, a third one of said positions coinciding with said thirdstation, fourth and fifth one of said positions being rest positionswith which no station corresponds, a sixth one of said positionscoinciding with said fourth station, a seventh one of said positionscoinciding with said fifth station and an eighth one of said positionscoinciding with said sixth station.
 6. The plant of claim 5, whereinsaid positioning means comprise a pawl chain connected to said eightcontainers and drive means for driving said pawl chain to thereby movesaid containers.
 7. The plant of claim 4, wherein said stations aremounted on a monorail and are movable along said monorail.
 8. The plantof claim 1, wherein said processing means and said positioning means arecontrolled by electronic control means.
 9. The plant of claim 8, whereinsaid electronic control means comprise at least one microprocessordevice.
 10. The plant of claim 1, wherein said processing means in atleast one of said stations comprise a proportioning device and liftingmeans for moving said proportioning device relative to said at least onecontainer when in said station, said proportioning device being arrangedto fill said at least one container when in said station with milk orwhey.
 11. The plant of claim 1, wherein said processing means in said atleast one station comprise lifting means for moving said heat exchangerrelative to said at least one container when in said station.
 12. Theplant of claim 1, wherein said processing means in said at least onestation further comprise first lifting means for moving said heatexchanger relative to said at least one container when in said station,a double proportioning device and second lifting means for moving saiddouble proportioning device relative to said at least one container whenin said station, said double proportioning device being arranged to feedsaid at least one container with milk ferments and curding liquid whenin said station.
 13. The plant of claim 1, wherein said processing meansin at least one of said stations comprise a variable-speed agitator,first lifting means for moving said agitator relative to said at leastone container when in said station, a variable-speed curd knife andsecond lifting means for moving said curd knife relative to said atleast one container when in said station.
 14. The plant of claim 1,wherein said processing means in said at least one station furthercomprise a variable-speed curd knife, first lifting means for movingsaid curd knife relative to said at least one container when in saidstation and second lifting means for moving said heat exchanger relativeto said at least one container when in said station.
 15. The plant ofclaim 1, wherein said processing means in at least one of said stationscomprise a variable-speed agitator and first lifting means for movingsaid agitator relative to said at least one container when in saidstation.
 16. A process for coagulating, pasteurizing and cooking foodhaving a liquid or pasty base, comprising the steps of:providing aplurality of stations, placing the food in at least one container,implementing a processing step on the food in said at least onecontainer in each of said stations, said processing step beingimplemented in at least one of said stations comprising the step ofengaging a variable-speed dynamic radial heat exchanger with the food insaid at least one station in order to affect the temperature of thefood, and successively positioning said at least one container in saidstations to thereby successively subject the food in said at least onecontainer to the processing step being implemented in each of saidstations.
 17. The method of claim 16, wherein the step of successivelypositioning said at least one container in said stations comprises thestep of maintaining said stations in a fixed position and moving said atleast one container into and out of said stations.
 18. The method ofclaim 16, wherein the step of successively positioning said at least onecontainer in said stations comprises the step of maintaining said atleast one container in a respective fixed position and moving saidstations relative to said at least one container.
 19. The method ofclaim 16, further comprising the step of movably mounting said stationson a monorail.
 20. The method of claim 16, further comprising the stepof controlling said processing step in each of said stations and saidpositioning step by electronic control means.